J144547-5931 and J144701-5919: Two massive stars in the Milky Way,
both about 9,000 light years from Earth. (Credit: X-ray: NASA/U. of Sydney/G.Anderson et al; IR: NASA/JPL-Caltech)

Caption: Data from Chandra and Spitzer of a region near the Galactic
plane have been combined to track down some of the Milky Way’s
heaviest stars, which can be very elusive. The outlined boxes contain
darkened Spitzer data and a bright Chandra X-ray source (blue) that
coincides with a strong infrared signal. These are giant stars
thought to be at least 25 times more massive than the Sun. They are
very bright in X-rays because high-speed winds from their surfaces
collide with material, creating shock waves that generate temperatures
up to 100 million degrees.